This invention relates to apparatus which utilizes ultraviolet light to cure inks and other ultraviolet-sensitive coatings on cans, containers and similar objects.
The use of ultraviolet light is not, of course, per se new.
U.S. Pat. No. 1,586,670 to Girard discloses an ultraviolet light for medical purposes in which the light is focused by means of prisms onto a conical pipe, thereby to be focused on a receiving surface.
Ultraviolet light sources have nbeen used to cure or treat a variety of surfaces. An early example may be found in U.S. Pat. No. 1,672,331 to Mailey in which ultraviolet light is used to cure varnished surfaces. A similar use of ultraviolet light is found in Brophy U.S. Pat. No. 2,020,296 which includes a source of ultraviolet about which a conveyor passes through 300.degree..
Jackson U.S. Pat. No. 3,934,500 discloses a multi-cylinder machine for printing on the surfaces of containers and ultraviolet light setting inks. One embodiment of the patent shows a fixed ultraviolet source having a shield or housing about which the containers pass. In another embodiment shown in that patent, each mandrel has an ultraviolet source with a curved reflector.
A more recent patent is U.S. Pat. No. 4,008,401 to Holloubek which discloses a curing system for tubular articles which are passed about a light source within a relfecting shield. In this patent, the tubular articles are stationary as they pass about the light source.